Semiconductor devices include one or more integrated circuits that can be used to store data, process electronic signals, etc. Such semiconductor devices are used in virtually all modern electronic devices. There are several different types of semiconductor devices used in modern electronics including, for example, memory devices, electronic signal processors, devices for capturing or acquiring images, etc. Each of these semiconductor devices may conventionally comprise capacitors used for storing an electrical charge.
One particular type of capacitor that has been used in such semiconductor devices is referred to as a “container” capacitor. A container capacitor includes a first conductive member or “plate” that is shaped like a container or a cup having a generally cylindrical side wall and a bottom wall, such that the container capacitor has a closed bottom and an open top. A second conductive member, which may have the shape of a generally cylindrical plug, may be provided within the first conductive member, and a dielectric material may be provided between the first conductive member and the second conductive member to allow a capacitance to be provided therebetween.
To increase the capacitance of such container capacitors, double-sided container capacitors have been developed. Double-sided container capacitors also include a first conductive member that is shaped like a container or a cup having a generally cylindrical side wall and a bottom wall, such that the container capacitor has a closed bottom and an open top. A layer of dielectric material is then provided over the interior and exterior surfaces of the first conductive member, and a second conductive member is formed that extends over the generally cylindrical side wall and extends adjacent to both the interior surface and the exterior surface of the first conductive member (the dielectric material being disposed therebetween). Thus, the second conductive member is disposed adjacent the inside surfaces and the outside surfaces of the first conductive member to form the double-sided container.
During the formation of such double-sided capacitors, the first conductive members are often formed by lining the exposed surfaces within generally cylindrical blind recesses formed in a relatively thick layer of dielectric material with conductive material. After forming the first conductive members, but prior to forming the second conductive members, the relatively thick layer of dielectric material surrounding the first conductive members is removed by, for example, a wet chemical etching process. However, after removing the relatively thick layer of dielectric material, the first conductive members are then laterally unsupported by solid material, since they are essentially free-standing and no longer laterally supported by the relatively thick layer of dielectric material. As a result, some of the free-standing first conductive members may lean together and contact one another prior to formation of the second conductive members, which may result in undesirable shorting between adjacent first conductive members.
In an effort to overcome these problems, a so-called “lattice layer” has been used to hold the open top ends of the first conductive members in place while the underlying relatively thick layer of dielectric material is removed from around the lateral sides of the first conductive members. In particular, the relatively thick layer of dielectric material may be provided on the semiconductor device in which the double-sided container capacitors are to be formed. A relatively thin lattice layer may be formed over the relatively thick layer of dielectric material, and generally cylindrical blind recesses then may be formed through the lattice layer and into the relatively thick layer of dielectric material. The first conductive members then may be formed by lining the exposed surfaces within the generally cylindrical blind recesses. Openings then may be formed through the lattice layer at selected locations to provide access to the underlying layer of dielectric material, and an etchant that will remove the layer of dielectric material without significantly removing the lattice layer may be used to remove the layer of dielectric material from underneath the lattice layer. In other words, the etchant will attack the layer of dielectric material through the holes formed at selected locations in the lattice layer, and will eventually remove the layer of dielectric material from underneath the lattice layer.
Even though the openings formed through the lattice layer at selected locations to provide access to the underlying layer of dielectric material may be located between adjacent conductive members of the capacitors such that at least a portion of each of the adjacent conductive members remains attached to the lattice layer, reagents used in subsequent processing steps (e.g., weak acids used in cleansing steps) may attack the interface between the lattice layer and the conductive members adjacent the openings formed through the lattice layer. As a result, the conductive members adjacent the openings in the lattice layer still may lean or collapse inward such that they touch adjacent conductive members, which may result in undesirable shorting between adjacent conductive members near the openings extending through the lattice layer.
For the reasons stated above and other reasons that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for improved methods of forming container capacitors in semiconductor devices.